Method and device for making a composite plate

Abstract

A process for manufacturing composite sheets includes steps of: continuously depositing a web of yarns, in the form of a mat of continuous yarns, a woven, a knit or an assembly of continuous non-interlaced yarns on a moving substrate; depositing a powder of an organic material capable of forming a coating layer under the action of heat on at least one side of said web; heating the web coated with the powder to a temperature sufficient to melt the powder; compressing and cooling the web so as to form a composite strip; and cutting the strip in the form of sheets or winding the strip up on a rotating support.

1. A process for manufacturing composite sheets, comprising the steps of:
 continuously depositing a web of continuous yarns on a moving substrate, the web comprising at least one first organic material and at least one reinforcing material; 
 depositing a powder of a second organic material on at least one surface of said web; 
 heating the web coated with the powder to a temperature sufficient to melt the powder into a smooth surface layer and melt said first organic material to form a matrix within which the reinforcing material is embedded; 
 compressing and cooling the web to form a composite strip formed of said matrix embedded with said reinforcing material and said smooth surface layer positioned on an external surface thereof; and 
 cutting the strip in the form of sheets or winding the strip on a rotating support. 
 
     
     
       2. The process as claimed in  claim 1 , wherein the powder is selected from the group consisting of particles of a thermoplastic material and particles of a thermosetting material. 
     
     
       3. The process as claimed in  claim 2 , wherein the thermoplastic material is selected from polyolefins, polyamides, polyesters and PVC. 
     
     
       4. The process as claimed in  claim 2 , wherein the thermosetting material is selected from epoxies, polyesters, polyurethanes and phenolic compounds. 
     
     
       5. The process as claimed in  claim 2 , wherein the web comprises between 20 and 90%, by weight of reinforcing material. 
     
     
       6. The process as claimed in  claim 5 , wherein the reinforcing material is glass, carbon or aramid. 
     
     
       7. The process as claimed in  claim 6 , wherein the web comprises at least 50% by weight of intermingled yarns of glass filaments and of filaments of a thermoplastic organic material capable of forming a matrix. 
     
     
       8. The process as claimed in  claim 7 , wherein the web is exclusively in the form of wovens or of continuous non-interlaced yarns. 
     
     
       9. The process as claimed in  claim 8 , wherein the powder is deposited on the web in an amount sufficient to produce a smooth surface layer with a thickness of between 0.3 and 1 mm. 
     
     
       10. The process as claimed in  claim 1 , wherein said web includes hybrid yarns formed of thermoplastic organic filaments and glass filaments. 
     
     
       11. The process of  claim 1 , wherein said composite strip has a width of approximately 1.5 meters. 
     
     
       12. A process for manufacturing composite sheets at least partly formed from intermingled yarns, comprising the steps of:
 continuously depositing a web of yarns, in the form of a mat of continuous yarns, the web being formed at least partly from intermingled yarns formed of filaments of a thermoplastic organic material and glass filaments intimately mixed; 
 depositing on at least one side of said web a powder of an organic material having a film-forming capability in an amount sufficient to form a smooth surface under the action of heat; 
 heating the web coated with the powder to a temperature high enough to convert the web of yarns into a matrix within which the glass filaments are embedded and to melt the powder into a topcoat having a smooth surface; and 
 compressing and cooling the web to form a composite strip. 
 
     
     
       13. The process of  claim 12 , wherein the powder of an organic material has an opacity sufficient to make the glass filaments in the matrix invisible. 
     
     
       14. The process of  claim 12 , wherein the step of depositing a powder further comprises depositing a powder on both sides of said web. 
     
     
       15. The process of  claim 12 , wherein the intermingled yarns comprise a woven material. 
     
     
       16. The process of  claim 12 , wherein the topcoat has a thickness between 0.3-1 mm. 
     
     
       17. The process of  claim 12 , wherein the filaments of a thermoplastic organic material and the powder of an organic material comprise the same material. 
     
     
       18. The process of  claim 17 , wherein the filaments of a thermoplastic material and the powder of an organic material comprise polypropylene. 
     
     
       19. The process of  claim 12 , wherein the web is compressed with a force of about 5 kN to 50 kN per meter of width. 
     
     
       20. The process of  claim 12 , further comprising the step of preventing interpenetration of the topcoat and the matrix by introducing an intermediate layer there between. 
     
     
       21. A process for manufacturing composite sheets, comprising the steps of:
 continuously depositing a web of continuous yarns on a moving substrate, said web comprising at least one first organic material and at least one reinforcing material; 
 depositing at least one intermediate structure on at least one surface of said web; 
 depositing a powder of a second organic material on said intermediate structure; 
 heating said web to a temperature sufficient to melt said powder into a smooth surface layer and melt said first organic material to form a matrix within which said reinforcing material is embedded; 
 compressing and cooling said web to form a composite strip; and 
 cutting the strip in the form of sheets or winding the strip on a rotating support. 
 
     
     
       22. The process as claimed in  claim 21 , wherein said at least one intermediate structure is selected from yarns or yarn assemblies, films, veils, sheets, panels and foams. 
     
     
       23. The process as claimed in  claim 21 , wherein said web includes hybrid yarns formed of thermoplastic organic filaments and glass filaments.